CN111771169A

CN111771169A - Mechanical watch oscillator

Info

Publication number: CN111771169A
Application number: CN201980011895.XA
Authority: CN
Inventors: 沃特·约翰内斯·本雅明·于普马; 西布伦·伦纳德·威克
Original assignee: Flexible Mechanism Ip Private Ltd
Current assignee: Flexible Mechanism Ip Private Ltd
Priority date: 2018-02-06
Filing date: 2019-01-28
Publication date: 2020-10-13
Anticipated expiration: 2039-01-28
Also published as: NL2020384B1; WO2019156552A1; JP7213270B2; JP2021514476A; EP3750009A1; CN111771169B

Abstract

A mechanical watch oscillator (100) comprising a platform (2), the platform (2) being provided with at least two vibrating masses (11, 12, 13) suspended on the platform (2), wherein each of the masses (11, 12, 13) is independently suspended on the platform (2) by at least one flexure member (21, 31; 22, 32; 23, 33), and wherein the at least two vibrating masses (11, 12, 13) are interconnected by two parallel flexure beams (41-48) to provide a direct torsionally rigid connection between the at least two vibrating masses (11, 12, 13), and wherein a first mass (11) of the at least two masses (11, 12, 13) and the at least one flexure member (21 or 31) providing the connection of the first mass (11) to the platform (2) are connected, relative to the at least two masses (11, 11, 12. 13) and at least one flexure member (22 or 32) providing the connection of the second mass (12) to the platform (2), wherein the mirror symmetry applies to a symmetry line (a) passing through the centre of the oscillator (100).

Description

Mechanical watch oscillator

Technical Field

The invention relates to a mechanical watch oscillator.

Background

Mechanical watch oscillators are known from WO2016/062889, WO2017/068538, EP 2273323, EP 3035126 and EP 3035127, to name a few.

WO2016/062889 discloses a mechanical watch movement regulating member comprising an escape wheel and a vibrating oscillator provided with at least two vibrating arms and a pallet solidly linked to said vibrating arms, and comprising two members arranged to interact directly with the teeth of the escape wheel, so as to maintain the periodic alternation of the vibrating oscillator and to advance the escape wheel with each alternation of oscillations. The vibrating masses in WO2016/062889 are not geometrically interconnected, which means that the amplitude and phase of oscillation of these masses do not remain in phase during impact, acceleration and/or orientation changes, which in turn causes timing inaccuracies.

WO2017/068538 discloses an oscillator for regulating a mechanical timepiece movement, the oscillator comprising an escape wheel and a resonator forming the time reference of the oscillator, the resonator comprising a mass element held in oscillation by at least two vibrating elements; the mass element comprises at least one anchor rigidly connected to the mass element and configured to engage directly with the escape wheel, to maintain the oscillation of the resonator and to allow the escape wheel to move with each alternation of oscillations. A disadvantage of the device of WO2017/068538 is that if there are two flexures or resilient suspensions falling on the ground, the device will have a high sensitivity to out-of-plane impacts (i.e. impacts perpendicular to the working plane). The center of mass of such a device with two flexures cannot be fixed. If there are more than two flexures, the device is unlikely to undergo significant deformation while maintaining isochronism (i.e., timing accuracy).

EP 2273323 discloses an oscillator comprising a fastening portion designed to be fastened to the frame of a timepiece and a plurality of elastic systems connecting the rim and the fastening portion to each other, wherein each elastic system comprises two return mechanisms arranged in series and connected to each other by the frame, wherein at least some of the elastic systems are suspended and free with respect to the frame. The oscillator of EP 2273323 comprises serially connected flexures having multiple degrees of freedom and therefore has a low impact resistance. Furthermore, such known oscillators are manufactured with features distributed in multiple planes, thereby increasing manufacturing and assembly difficulties.

EP 3035126 discloses a timepiece resonator with oscillating weights, wherein the resonator can be mounted on a timepiece, wherein the weights are suspended by crossed elastic strips extending at a distance from each other in parallel planes, wherein the resonator is of the tuning fork type with at least two weights oscillating in a symmetrical manner. This known device with two elementary flexures will have a very low resistance to out-of-plane impacts, i.e. impacts perpendicular to the working plane. In addition, the oscillator is manufactured with features distributed in multiple planes, thereby increasing manufacturing and assembly difficulties.

EP 3035127 discloses a timepiece oscillator with a tuning fork type resonator, comprising at least two movable oscillating parts fixed with flexure elements to a connecting element comprised in the oscillator, wherein each movable part oscillates about a virtual pivot, and wherein the center of mass of the movable part coincides with the virtual pivot in its rest position, and wherein the flexure elements of at least one movable part are formed by intersecting elastic strips. In this known device, the vibrating masses are not geometrically interconnected, which means that the oscillations of these masses do not remain in phase during shocks, accelerations and/or orientation changes, which ultimately results in timing inaccuracies. Furthermore, the known oscillator is manufactured with features distributed in multiple planes, thereby increasing manufacturing and assembly difficulties.

Disclosure of Invention

It is an object of the present invention to provide a mechanical watch oscillator that is highly resistant to the effects of changes in attractive forces due to different orientations of the oscillator.

It is another object of the present invention to provide a mechanical watch oscillator having high impact resistance.

It is a further object of the present invention to provide a mechanical watch oscillator that may be smaller in size than prior art oscillators.

These and other objects of the invention, which will become apparent from the following disclosure, are achieved by a mechanical watch oscillator according to one or more of the appended claims.

In a first aspect of the invention, a mechanical watch oscillator comprises a platform provided with at least two vibrating masses suspended from the platform, wherein each of the masses is suspended from the platform by at least one flexure member, and wherein the at least two seismic masses are connected to one another by at least two parallel flexural beams, the at least two parallel flexure beams provide a direct torsionally rigid connection between the at least two vibrating masses, and wherein a first mass of the at least two masses and the at least one flexure member providing the connection of the first mass to the platform are substantially mirror symmetric with respect to a second mass of the at least two masses and the at least one flexure member providing the connection of the second mass to the platform, and wherein the mirror symmetry applies to a line of symmetry passing through a center of the oscillator. The word "substantially" in the preceding sentence means: both expected and unexpected errors with respect to the weight or shape of the mass and with respect to the orientation of the flexure members providing the connection of the mass to the platform are included within the scope of the present invention. From an engineering point of view, errors of up to 10% of the nominal value are tolerable without departing from the scope of the invention. In terms of the orientation of the flexing member, a difference in orientation of 10% of a full 360 ° turn is tolerable without departing from the scope of the present invention. Of course, the best results are obtained in the case of perfect mirror symmetry and in the case of masses having exactly equal weight and shape.

The aforementioned features are implemented in combination: the mechanical watch oscillator of the present invention is highly resistant to gravitational effects that may occur in connection with different orientations of the oscillator.

In a second aspect of the invention, which can be adapted for use alone, or in combination with the features according to the above first aspect of the invention, or in combination with any of the following features to be discussed hereinafter, a mechanical watch oscillator comprises a platform provided with at least two vibrating masses suspended from the platform, wherein each of the masses is suspended from the platform by at least one flexure member, and wherein the at least two vibrating masses are interconnected by at least two parallel flexure beams to provide a direct torsionally rigid connection between the at least two vibrating masses, and wherein the two parallel flexure beams are rotationally symmetric only about a full or half turn of the oscillator. Wikipedia defines the following features of rotational symmetry, also considered in biology as radial symmetry, i.e. as shape: the shape looks the same after a partial rotation. The degree of rotational symmetry of an object refers to the number of different orientations in which the object appears to be the same. Thus, in the present invention, the feature "rotationally symmetric only about a full or half revolution of the oscillator" means: it is necessary to rotate the oscillator a full 360 deg. or 180 deg., until the oscillator again has the same shape or appearance as when the oscillator has been rotated 0 deg., i.e., when the oscillator has not been rotated. The combined features allow the oscillator to be made smaller and cheaper or alternatively allow the oscillator to provide space for other features such as, for example, an escape wheel within the circumference provided by the vibrating mass of the oscillator. The oscillator may also be more energy efficient or consume less energy due to the possible reduction in size, and the oscillator provides better durability and better shock resistance due to reduced mass.

The following features may be applied with the mechanical oscillator according to the above first aspect of the present invention, or may be used in combination with the mechanical oscillator according to the above second aspect of the present invention. All features discussed herein may also be applied cumulatively.

Preferably, the at least two masses are interconnected by two sets of two parallel flexure beams, the two sets being arranged in series and preferably having equal lengths. Each set of individual flexure beams allows relative translation between the two ends of each set of flexure beams. Because the two sets of flexure beams are arranged in series, both ends of each set of flexure beams can move in both translational directions, thereby spanning a surface, but rotation between the two ends of each set of flexure beams is avoided. By mounting the two sets of parallel flexure beams between the two masses, equal amplitude vibration with zero phase shift is geometrically ensured between the two masses, which is advantageous for maintaining the stability of the center of mass of the oscillator and for improving the shock resistance of the oscillator.

In a preferred embodiment, at least one of the masses is independently suspended from the platform by two flexure members. This also increases the shock resistance of the oscillator. Preferably, all the masses of the oscillator are each suspended from the platform by two flexure members to further improve the shock resistance of the oscillator.

In embodiments where the number of masses is counted n, it is preferred that all masses are connected to each other by at least n-1 sets of interconnects between the masses, wherein each set of interconnects comprises at least two parallel flexures. This completely limits the rotation of the mass parts relative to each other.

At least some of the objects of the invention are further pursued in the following embodiments: in this embodiment, a first mass of the at least two masses and the two flexure members providing the connection of the first mass to the platform and a second mass of the at least two masses and the two flexure members providing the connection of the second mass to the platform are mirror symmetric according to two symmetry lines orthogonal to each other.

Preferably, the at least one flexure member for each of the masses to be independently suspended from the platform and the at least two parallel flexure beams providing a direct torsionally rigid connection between the at least two vibrating masses have rigid sections. This feature increases the impact level when the flexure members and flexure beams are bent.

The impact resistance is further improved by the following arrangement: the at least two vibrating masses have a first mechanical stop arranged to limit displacement of the vibrating masses relative to the platform.

In this respect it is further advantageous if the at least two seismic masses have a second mechanical stop, which is arranged to limit the displacement of the seismic masses relative to one another.

The mechanical resistance to relative movement as described in the preceding two paragraphs reduces the stress in the flexure member and beam and reduces the risk of breakage.

Drawings

The invention will be further explained hereinafter with reference to the drawings of several exemplary embodiments of a timepiece oscillator according to the invention, which are not limited to the appended claims.

In the drawings:

figures 1A and 1B show a first embodiment of a timepiece oscillator according to the invention in plan view and isometric view, respectively;

figures 2A and 2B show a second embodiment of the timepiece oscillator according to the invention in plan view and isometric view, respectively;

figures 3A and 3B show a third embodiment of the timepiece oscillator according to the invention in plan view and isometric view, respectively;

fig. 4 shows, in plan view, a fourth embodiment of a timepiece oscillator according to the invention; and the number of the first and second groups,

fig. 5 shows, in plan view, a fifth embodiment of the timepiece oscillator according to the invention.

Whenever the same reference numerals are used in the drawings, they refer to the same parts.

Detailed Description

Turning first to fig. 1A, 1B, 2A and 2B, two different embodiments are shown, wherein an oscillator 100 has two

masses

11, 12, which

masses

11, 12 are elastically suspended to a platform 2 by means of thin

flexible elements

21, 31 and 22, 32.

With reference to the two embodiments of fig. 1A, 1B, 2A and 2B, the platform 2 of the oscillator 100 is provided with screw holes 61, 62, with which the oscillator 100 can be connected to the rest of the timepiece.

When the

masses

11, 12 vibrate, the extensions 51, 52 of these

masses

11, 12 alternately release the escape wheel 53 and block the escape wheel 53, allowing the escape wheel to rotate step by step. The oscillator 100 is kept in oscillatory motion by the energy input from the escape wheel 53.

The difference between the embodiments shown in fig. 1A, 1B and fig. 2A and 2B is that in the embodiment of fig. 1A and 1B, the platform 2 is placed in the center of the oscillator 100, whereas in the embodiment of fig. 2A and 2B, the platform 2 is placed at the periphery of the oscillator 100.

It is worth noting that although the

masses

11, 12 are each shown separately connected to the platform 2 using two flexure elements 21, 31 and two

flexure elements

22, 32, respectively, this represents the most preferred embodiment that provides the best shock resistance for the oscillator 100, it is sufficient within the scope of the present invention that the

masses

11, 12 are each separately connected to the platform 2 using a single flexure element. As an example: it is sufficient to apply only the flexible element 21 or only the flexible element 31 for the mass 11, and it is sufficient to apply only the flexible element 22 or only the flexible element 32 for the mass 12.

However, according to the first aspect of the invention, it is essential that the first mass 11 of the at least two masses and the at least one flexure member 21, 31 providing the connection of the first mass 11 to the platform 2 are mirror symmetric with respect to the second mass 12 of the at least two masses and the at least one

flexure member

22, 32 providing the connection of the second mass 12 to the platform 2, wherein the mirror symmetry applies with respect to a symmetry line a passing through the center of the oscillator 100. This provides a high resistance to gravitational effects, such as oscillation frequency, due to changes in the orientation of the oscillator 100 of the present invention.

If the embodiment as shown in fig. 1A, 1B and 2A and 2B is provided with

masses

11, 12 connected to the platform 2 using two flexible elements 21, 31 and two

flexible elements

22, 32, respectively, it is preferred that the first mass 11 of the at least two masses and the two flexure members 21, 31 providing the connection of the first mass 11 to the platform 2 are mirror symmetric according to both a symmetry line a and a symmetry line B orthogonal to each other, and the second mass 12 of the at least two masses and the two

flexure members

22, 32 providing the connection of the second mass 12 to the platform 2. This further increases the insensitivity of the oscillator 100 to gravitational effects due to the different orientations of the oscillator 100 of the present invention.

As further shown in the two embodiments of fig. 1A, 1B and 2A and 2B, the two

masses

11, 12, which represent all the masses in these embodiments, are preferably interconnected by two sets of parallel flexure beams: a set of two parallel flexure beams 41, 42 of equal length and a set of two parallel flexure beams 43, 44 of equal length, respectively. A separate set of flexure beams 41, 42 and a separate set of flexure beams 43, 44 each only allow relative translation between the two ends of each set of flexure beams. Because the two sets of flexure beams are arranged in series, both ends of the set of flexure beams can move in both translational directions, thereby spanning a surface, but rotation between the two ends of each set of flexure beams is avoided.

By mounting the set of parallel flexure beams 41, 42 and the set of parallel flexure beams 43, 44 between the two

mass parts

11, 12, equal amplitude vibrations with zero phase shift are geometrically ensured between the two

mass parts

11, 12, which is beneficial for maintaining the stability of the center of mass of the oscillator 100 and for improving the shock resistance of the oscillator.

According to a second aspect of the invention, the parallel flexure beams 41-44 in the embodiments of fig. 1A, 1B and 2A and 2B are rotationally symmetric only about a full or half turn of the oscillator 100, providing space for the escape wheel 53 and the vibration extensions 51, 52. The space can of course also be used for other features as desired.

A third embodiment of the oscillator 100 of the present invention is shown in fig. 3A and 3B, wherein the oscillator 100 of fig. 3A and 3B is provided with an additional mass 13 compared to the embodiment of fig. 1A and 1B. The foregoing description of the mirror symmetry of the

masses

11 and 12 and the flexures connecting the

masses

11 and 12 to the platform 2 according to the first aspect of the invention also applies to this embodiment of fig. 3A and 3B. Specifically, the method comprises the following steps: also shown in fig. 3A and 3B, the first mass 11 and the at least one flexible member 21 or 31 providing the connection of the first mass 11 to the platform 2 are mirror-symmetrical with respect to the second mass 12 and the at least one

flexible member

22 or 32 providing the connection of the second mass 12 to the platform 2, wherein the mirror-symmetry applies to an axis of symmetry a passing through the center of the oscillator 100. Likewise, the second aspect of the invention, which relates to the parallel flexure beams 41-48 being rotationally asymmetric and symmetric only about a full rotation of the oscillator 100, is also applicable in this embodiment, so that space is also provided for the escape wheel 53 and the vibrating extensions 51, 52 in this embodiment.

Similar to the third embodiment shown in fig. 3A and 3B, the fourth embodiment shown in fig. 4 is provided with a first mass member 11, a second mass member 12, and an additional mass member 13. This fourth embodiment differs from the previously discussed embodiments in that it shows another possibility of connecting the masses to each other, wherein two parallel flexure beams 41, 42 connect the two vibrating

masses

11 and 13 and two parallel flexure beams 47, 48 connect the two vibrating

masses

12, 13. Further according to the first aspect of the invention, in this embodiment the first mass 11 and the flexure 31 providing the connection of the first mass 11 to the platform 2 are substantially mirror symmetric with respect to the second mass 12 and the flexure 22 providing the connection of the second mass 12 to the platform 2, wherein said mirror symmetry applies to a symmetry line a passing through the centre of the oscillator 100. Also according to a second aspect of the invention, the parallel flexure beams 41-48 in the embodiment of fig. 3A, 3B are implemented rotationally symmetric only about a full or half turn of the oscillator 100.

Finally, a fifth embodiment with enhanced in-plane impact robustness is shown in fig. 5, wherein at least one flexing member 21, 31; 22. 32 and at least two parallel flexure beams 41-44 having rigid sections 21a, 31 a; 22a, 32 a; 41a-44a, wherein each of the

masses

11, 12 is connected to the mass by the at least one flexure member 21, 31; 22. 32 are individually suspended from the platform 2, the at least two parallel flexure beams 41-44 providing a direct torsionally rigid connection between the at least two

seismic masses

11, 12. These rigid sections increase the impact level when the flexure member and flexure beam are bent.

It is further shown that the at least two vibrating

masses

11, 12 have first mechanical stops 11a, 12a, the first mechanical stops 11a, 12a being arranged to limit the displacement of the vibrating

masses

11, 12 relative to the platform 2, and that the at least two vibrating

masses

11, 12 have second mechanical stops 11b, 12b, the second mechanical stops 11b, 12b being arranged to limit the displacement of the vibrating

masses

11, 12 relative to each other. The mechanical resistance to said relative movement reduces the stress in the flexure member and the beam and reduces the risk of breakage of the flexure member and the beam. Although the invention has been discussed above with reference to a few exemplary embodiments of the oscillator of the invention, the invention is not limited to these particular embodiments, which may be further varied in many ways without departing from the invention. Accordingly, the exemplary embodiments discussed should not be used strictly accordingly to construe the claims below. Rather, the embodiments are intended merely to interpret the words of the appended claims and are not intended to limit the claims to these exemplary embodiments. The scope of protection of the invention should therefore be interpreted solely in accordance with the appended claims, wherein ambiguities that may exist in the wording of the claims should be resolved with these exemplary embodiments.

Claims

1. A mechanical watch oscillator (100), the mechanical watch oscillator (100) comprising a platform (2), the platform (2) being provided with at least two vibrating masses (11, 12, 13) suspended on the platform (2), wherein each of the masses (11, 12, 13) is independently suspended on the platform (2) by at least one flexure member (21, 31; 22, 32; 23, 33), and wherein at least two vibrating masses (11, 12, 13) are interconnected by at least two parallel flexure beams (41-48), the at least two parallel flexure beams (41-48) providing a direct torsional rigid connection between the at least two vibrating masses (11, 12, 13), and wherein a first mass (11) of the at least two masses (11, 12, 13) and at least one flexure providing a connection of the first mass (11) to the platform (2) The member (21 or 31) is substantially mirror-symmetrical with respect to a second mass (12) of the at least two masses (11, 12, 13) and at least one flexure member (22 or 32) providing the connection of the second mass (12) to the platform (2), wherein the mirror-symmetry applies to a symmetry line (a) passing through the centre of the oscillator (100).

2. A mechanical watch oscillator (100), the mechanical watch oscillator (100) comprising a platform (2), the platform (2) is provided with at least two seismic mass elements (11, 12, 13) suspended on the platform (2), wherein each of the masses (11, 12, 13) is independently suspended from the platform (2) by at least one flexure member (21, 31; 22, 32; 23, 33), and wherein at least two vibrating mass elements (11, 12, 13) are interconnected by at least two parallel flexural beams (41-48), the at least two parallel flexural beams (41-48) providing a direct torsionally rigid connection between the at least two seismic masses (11, 12, 13), and wherein the two parallel flexure beams (41-48) are rotationally symmetric only about a full or half turn of the oscillator (100).

3. The mechanical watch oscillator (100) of claim 1, wherein the two parallel flexure beams (41-48) are rotationally symmetric only about a full or half turn of the oscillator (100).

4. Mechanical watch oscillator (100) according to any of claims 1 to 3, wherein the at least two masses (11, 12) are interconnected by two parallel flexure beams (41-48) of two groups, which are arranged in series and preferably have equal length.

5. Mechanical watch oscillator (100) according to any of claims 1 to 4, wherein at least one of the masses (11, 12, 13) is independently suspended from the platform (2) by two flexure members (21, 31; 22, 32; 23, 33).

6. Mechanical watch oscillator (100) according to any of claims 1 to 5, wherein all masses (11, 12, 13) of the oscillator (100) are independently suspended from the platform (2) by two flexure members (21, 31; 22, 32; 23, 33).

7. Mechanical watch oscillator (100) according to any of the claims 1 to 6, wherein if the number of masses is counted n, all masses (11, 12, 13) are connected to each other by at least n-1 sets of interconnects between the masses (11, 12, 13), wherein each set of interconnects comprises at least two parallel flexural beams (41-48).

8. Mechanical watch oscillator (100) according to any of the claims 3 to 7, wherein the first mass (11) of the at least two masses (11, 12, 13) and the two flexure members (21, 31) providing the connection of the first mass (11) with the platform (2) and the second mass (12) of the at least two masses (11, 12, 13) and the two flexure members (22, 32) providing the connection of the second mass (12) with the platform (2) are mirror symmetric according to two symmetry lines (A, B) orthogonal to each other.

9. Mechanical watch oscillator (100) according to any of the claims 1 to 8, wherein the at least one flexure member (21, 31; 22, 32) for suspending each of the masses (11, 12, 13) independently on the platform (2) and the two parallel flexure beams (41-44) providing a direct torsional rigid connection between the at least two vibrating masses (11, 12) have rigid sections (21a, 31 a; 22a, 32 a; 41a-44 a).

10. Mechanical watch oscillator (100) according to any of the claims 1 to 9, wherein the at least two vibrating masses (11, 12) have first mechanical stops (11a, 12a), the first mechanical stops (11a, 12a) being arranged to limit the displacement of the vibrating masses (11, 12) with respect to the platform (2).

11. Mechanical watch oscillator (100) according to any of the claims 1 to 10, wherein the at least two vibrating masses (11, 12) have second mechanical stops (11b, 12b), the second mechanical stops (11b, 12b) being arranged to limit the displacement of the vibrating masses (11, 12) with respect to each other.